Process for the simultaneous hydroconversion of a first feedstock comprising unsaturated, halogenated organic compounds and a second feedstock comprising saturated, halogenated organic compounds

ABSTRACT

A process for the simultaneous hydroconversion of a first feedstock comprising unsaturated, halogenated organic compounds and a second feedstock comprising saturated, halogenated organic compounds which process comprises: (a) contacting the first feedstock comprising unsaturated, halogenated organic compounds with a first dried hydrogen-rich gas stream in a first hydrogenation reaction zone operated at hydrogenation conditions selected to minimize the polymerization of unsaturated organic compounds and to produce a first hydrogenated stream comprising hydrocarbonaceous compounds; (b) reacting at least a portion of the first hydrogenated stream comprising hydrocarbonaceous compounds and the second feedstock comprising saturated, halogenated organic compounds with hydrogen in a second hydrogenation reaction zone operated at hydrogenation conditions selected to produce a second hydrogenated stream comprising hydrocarbonaceous compounds and to generate at least one water-soluble hydrogen halide compound; (c) contacting the the second hydrogenated stream with a halide-lean absorber solution in an absorption zone; (d) withdrawing a halide-rich absorber solution containing at least a portion of the water-soluble hydrogen halide compound from the absorption zone; (e) withdrawing a stream comprising hydrogenated hydrocarbonaceous compounds and a hydrogen-rich gas from the absorption zone; (f) introducing the stream recovered in step (e) into a separation zone to produce a hydrogen-rich gas stream comprising water vapor and a third hydrogenated stream comprising hydrocarbonaceous compounds; (g) removing at least a portion of the water vapor from the hydrogen-rich gas stream comprising water vapor in a drying zone to produce a second dried hydrogen-rich gas stream; and (h) recycling at least a portion of the second dried hydrogen-rich gas stream to step (a) as the first dried hydrogen-rich gas stream.

BACKGROUND OF THE INVENTION

The field of art to which this invention pertains is the production of ahydrogenated hydrocarbonaceous product from an unsaturated, halogenatedorganic feed and a saturated, halogenated organic feed.

More specifically, the invention relates to a process for thesimultaneous hydroconversion of a first feedstock comprisingunsaturated, halogenated organic compounds and a second feedstockcomprising saturated, halogenated organic compounds which processcomprises: (a) contacting the first feedstock comprising unsaturatedhalogenated organic compounds with a first dried hydrogen-rich gasstream in a first hydrogenation reaction zone operated at hydrogenationconditions selected to minimize the polymerization of unsaturatedorganic compounds and to produce a first hydrogenated stream comprisinghydrocarbonaceous compounds; (b) reacting at least a portion of thefirst hydrogenated stream comprising hydrocarbonaceous compounds and thesecond feedstock comprising saturated, halogenated organic compoundswith hydrogen in a second hydrogenation reaction zone operated athydrogenation conditions selected to produce a second hydrogenatedstream comprising hydrocarbonaceous compounds and to generate at leastone water-soluble hydrogen halide compound; (c) contacting the thesecond hydrogenated stream with a halide-lean absorber solution in anabsorption zone; (d) withdrawing a halide-rich absorber solutioncontaining at least a portion of the water-soluble hydrogen halidecompound from the absorption zone; (e) withdrawing a stream comprisinghydrogenated hydrocarbonaceous compounds and a hydrogen-rich gas fromthe absorption zone; (f) introducing the stream recovered in step (e)into a separation zone to produce a hydrogen-rich gas stream comprisingwater vapor and a third hydrogenated stream comprising hydrocarbonaceouscompounds; (g) removing at least a portion of the water vapor from thehydrogen-rich gas stream comprising water vapor in a drying zone toproduce a second dried hydrogen-rich gas stream; and (h) recycling atleast a portion of the second dried hydrogen-rich gas stream to step (a)as the first dried hydrogen-rich gas stream.

There is a steadily increasing demand for technology which is capable ofthe simultaneous hydroconversion of a first feedstock comprisingunsaturated, halogenated organic compoounds and a second feedstockcomprising saturated halogenated organic compounds. Previous techniquesutilized to dispose of such feedstocks which are often undesirableby-products of other processes such as epichlorohydrin production, forexample, have frequently become environmentally unpopular or illegaland, in general, have always been expensive. With the increasedenvironmental emphasis for the treatment and recycle of chlorinatedorganic products, there is an increased need for the conversion of theseproducts in the event that they become unwanted or undesirable. Forexample, during the disposal or recycle of potentially environmentallyharmful halogenated organic waste streams, an important step in thetotal solution to the problem is the conditioning of the halogenatedorganic stream which facilitates the ultimate resolution to provideproduct streams which may be handled in an environmentally acceptablemanner. Frequently, the subsequent use of a hydrocarbonaceous effluentfrom a halogenated organic waste stream conversion process demands thatthe effluent contain essentially no organic halide compounds. Therefore,those skilled in the art have sought to find feasible techniques tohydroconvert unsaturated and saturated halogenated organic compounds toprovide hydrocarbonaceous product streams which may be safely andusefully employed or recycled. Previous techniques which have beenemployed include incineration which in addition to potential pollutionconsideration fails to recover valuable hydrocarbonaceous materials.

INFORMATION DISCLOSURE

In U.S. Pat. No. 3,592,864 ( Gewartowski), a process is disclosed forhydrogenating benzene to form cyclohexane utilizing once-throughhydrogen-containing gas wherein the exothermic heat of reaction isutilized as the sole source of heat input to steam generation means andwherein the processing system is enhanced by the elimination of recyclegas compressor, treaters, coolers and heaters.

In U.S. Pat. No. 3,133,013 (Watkins), a process is disclosed whichrelates to the hydrorefining of hydrocarbons for the purpose of removingdiverse contaminants therefrom and/or reacting such hydrocarbons toimprove the chemical and physical characteristics thereof, In addition,the process is directed toward the selective hydrogenation ofunsaturated, coke-forming hydrocarbons through the use of particularconditions whereby the formation of coke, otherwise resulting from thehydrorefining of such hydrocarbon fractions and distillates, iseffectively inhibited.

BRIEF SUMMARY OF THE INVENTION

The invention provides an improved process for the production of ahydrogenated hydrocarbonaceous product from an unsaturated, halogenatedorganic feed and a saturated, halogenated organic feed by means ofcontacting the unsaturated organic feed in a first hydrogenationreaction zone at hydrogenation conditions selected to saturate thefeedstock with a dried hydrogen-rich gas while minimizing thepolymerization of the unsaturated halogenated organic compounds and tocontact the effluent from the first hydrogenation zone and thesaturated, halogenated organic feed in a second hydrogenation reactionzone at hydrogenation conditions to produce a hydrogenatedhydrocarbonaceous product and at least one water-soluble hydrogen halidecompound. The present invention provides a convenient and economicalmethod for the recovery of the water-soluble hydrogen halide compound(s)which are produced in the hydrogenation reaction zones. Importantelements of the process are the integrated hydrogenation reaction zoneswhich reduce capital and utility costs, and the elimination or at leastthe minimization of the polymerization of unsaturated halogenatedorganic compounds which prevents excessive buildup of carbonaceousdeposits in the processing equipment and on the catalyst, improves therecovery of hydrogen halide compounds and maximizes the quantity ofhydrogenated hydrocarbonaceous product. The use of a dried hydrogen-richgas prevents corrosion in the hydrogenation zones and thereby preventsequipment failure, reduces maintenance and permits lower plantconstruction costs.

One embodiment of the invention may be characterized as a process forthe simultaneous hydroconversion of a first feedstock comprisingunsaturated, halogenated organic compounds and a second feedstockcomprising saturated, halogenated organic compounds which processcomprises: (a) contacting the first feestock comprising unsaturated,halogenated organic compounds with a first dried hydrogen-rich gasstream in a first hydrogenation reaction zone operated at hydrogenationconditions selected to minimize the polymerization of unsaturatedorganic compounds and to product a first hydrogenated stream comprisinghydrocarbonaceous compounds; (b) reacting at least a portion of thefirst hydrogenated stream comprising hydrocarbonaceous compounds and thesecond feedstock comprising saturated, halogenated organic compoundswith hydrogen in a second hydrogenation reaction zone operated athydrogenation conditions selected to produce a second hydrogenatedstream comprising hydrocarbonaceous compounds and to generate at leastone water-soluble hydrogen halide compound; (c) contacting the thesecond hydrogenated stream with a halide-lean absorber solution in anabsorption zone; (d) withdrawing a halide-rich absorber solutioncontaining at least a portion of the water-soluble hydrogen halidecompound from the absorption zone; (e) withdrawing a stream comprisinghydrogenated hydrocarbonaceous compounds and a hydrogen-rich gas fromthe absorption zone; (f) introducing the stream recovered in step (e)into a separation zone to produce a hydrogen-rich gas stream comprisingwater vapor and a third hydrogenated stream comprising hydrocarbonaceouscompounds; (g) removing at least a portion of the water vapor from thehydrogen-rich gas stream comprising water vapor in a drying zone toproduce a second dried hydrogen-rich gas stream; and (h) recycling atleast a portion of the second dried hydrogen-rich gas stream to step (a)as the first dried hydrogen-rich gas stream.

Other embodiments of the present invention encompass further suchdetails such as preferred feedstocks, hydrogenation catalysts,adsorbents, absorber solutions and operating conditions, all of whichare hereinafter disclosed in the following discussion of each of thesefacets of the invention.

BRIEF DESCRIPTION OF THE DRAWING

The drawing is a simplified process flow diagram of a preferredembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides an improved integrated process for thesimultaneous hydroconversion of a first feedstock comprisingunsaturated, halogenated organic compounds and a second feedstockcomprising saturated, halogenated organic compounds. A wide variety ofhalogenated organic compounds, both unsaturated and saturated, arecandidates for feed streams in accordance with the process of thepresent invention. Examples of organic streams comprising halogenatedorganic compounds which are suitable for treatment by the process of thepresent invention are dielectric fluids, hydraulic fluids, heat transferfluids, used lubricating oil, used cutting oils, used solvents,halogenated hydrocarbonaceous by-products, oils contaminated withpolychlorinated biphenyls (PCB), halogenated wastes, petrochemicalby-products and other halogenated hydrocarbonaceous industrial wastes.Often, in a particular place or location, two or more halogenatedorganic streams are present and require further treatment. It has beendiscovered that unsaturated halogenated organic compounds present agreater challenge for subsequent processing such as hydrogenation ascompared with the saturated halogenated organic compounds. When bothtypes of halogenated organic streams are present, they may readily beprocessed in the integrated hydrogenation process of the presentinvention. The halogenated organic feed streams which are contemplatedfor use in the present invention may also contain organic compoundswhich include sulfur, oxygen, nitrogen or metal components which may besimultaneously hydrogenated to remove or convert such components asdesired. The halogenated organic compounds may also contain hydrogen andare therefore then referred to as hydrocarbonaceous compounds.

Preferred feedstocks containing unsaturated, halogenated organiccompounds comprise a component selected from the group consisting offractionation column bottoms in the production of ally chloride,fractionation column bottoms in the production of ethylene dichloride,fractionation column bottoms in the production of trichloroethylene andperchloroethylene, used dielectric fluid containing polychlorinatebiphenyls (PCB) and chlorinated benzene, used chlorinated solvents, andmixtures thereof.

Preferred feedstocks containing saturated, halogenated organic compoundscomprise a component selected from the group consisting of fractionationbottoms from the purification column in epichlorohydrin production,carbon tetrachloride, 1,1,1 trichloroethane, chlorinated alcohols,chlorinated ethers, chlorofluorocarbons and admixtures thereof.

The halogenated organic compounds which are contemplated as feedstocksin the present invention preferably contain a halogen selected from thegroup consisting of chlorine and fluorine.

In accordance with the present invention, a feedstock comprisingunsaturated, halogenated organic compounds is introduced in admixturewith a dried hydrogen-rich gas stream into a catalytic hydrogenationzone containing hydrogenation catalyst and maintained at mildhydrogenation conditions. This catalytic hydrogenation zone may containa fixed, ebullated or fluidized catalyst bed. This reaction zone ispreferably maintained at mild conditions which are chosen to selectivelysaturate unsaturated organic compounds such as olefins and diolefins,for example, while simultaneously preventing the formation of polymersor higher molecular weight carbonaceous material. Preferred reactionzone conditions include an imposed pressure from about atmospheric (0kPa gauge) to about 2,000 psig (13790 kPa gauge) and more preferablyunder a pressure from about 100 psig (689.5 kPa gauge) to about 1800psig (12411 kPa gauge). Suitably, such reaction is conducted with amaximum catalyst bed temperature in the range of about 122° F. (50° C.)to about 650° F. (343° C.) selected to perform the desired saturation ofunsaturated organic compounds in order to reduce or eliminate thepropensity of the unsaturated feed stream to form polymers and gum whichare undesirable for further use or processing of the resultinghydrocarbonaceous stream. Although the primary function of thishydrogenation zone is used to saturate the unsaturated halogenatedorganic charge stream, it is also contemplated in accordance with thepresent invention that the desired hydrogenation conversion may alsoinclude, for example, dehalogenation, desulfurization, denitrification,oxygenate conversion and hydrocracking. Further preferred operatingconditions include liquid hourly space velocities in the range fromabout 0.05 hr.⁻¹ to about 20 hr.⁻¹ and hydrogen circulation rates fromabout 200 standard cubic feed per barrel (SCFB) (33.71 normal m³ /m³) toabout 100,000 SCFB (16851 normal m³ /m³), preferably from about 300 SCFB(50.6 normal m³ /m³) to about 50,000 SCFB (8427 normal m³ /m³).

The resulting effluent from the first hydrogenation reaction zone whichis used to hydrogenate and saturate the unsaturated organic feedstock isadmixed with the saturated, halogenated organic feed stream withoutintermediate separation thereof and the resulting admixture isintroduced into a second catalytic hydrogenation zone containinghydrogenation catalyst and maintained at hydrogenation conditions. Thissecond catalytic hydrogenation zone may contain a fixed, ebullated orfluidized catalyst bed. The operating conditions selected for thiscatalytic hydrogenation zone are selected primarily to dehalogenate thehalogenated organic compounds which are introduced thereto and theseoperating conditions are generally more severe, i.e., promote greaterhydrogenation than the operating conditions utilized in the firstcatalytic hydrogenation zone. This second catalytic hydrogenation zoneis preferably maintained under an imposed pressure from aboutatmospheric (0 kPa gauge) to about 2000 psig (13790 kPa gauge) and morepreferably under a pressure from about 100 psig (689.5 kPa gauge) toabout 1800 psig (12411 kPa gauge). Suitably, such reaction is conductedwith a maximum catalyst bed temperature in the range of about 122° F.(50° C.) to about 850° F. (454° C.) selected to perform the desiredhydrogenation and dehalogenation conversion to reduce or eliminate theconcentration of halogenated organic compounds contained in the combinedfeed stream. In accordance with the present invention, it iscontemplated that the desired hydrogenation conversion includes, forexample, dehalogenation, desulfurization, denitrification, oxygenateconversion and hydrocracking. Further preferred operating conditionsinclude liquid hourly space velocities in the range from about 0.05hr.⁻¹ to about 20 hr.⁻¹ and hydrogen circulation rates from about 200standard cubic feed per barrel (SCFB) (33.71 normal m³ /m³) to about100,000 SCFB (16851 normal m³ /m³), preferably from about 200 SCFB(33.71 normal m³ /m³) to about 50,000 SCFB (8427 normal m³ /m³).

In the event that the temperature of the combined halogen-containing,organic feed stream which is introduced into the second hydrogenationreaction zone is not deemed to be exactly the temperature selected tooperate the second catalytic hydrogenation zone, we contemplate that thetemperature of the feed stream to be introduced into the hydrogenationzone may be adjusted either upward or downward in order to achieve thedesired temperature in the catalytic hydrogenation zone. Such atemperature adjustment may be accomplished, for example, by eitherindirect heat exchange or by the addition of either cool or hothydrogen.

In accordance with the present invention, the hydrocarbonaceous effluentcontaining at least one water-soluble hydrogen halide compound from thesecond hydrogenation zone is contacted with an absorber solution torecover the water-soluble hydrogen halide compound and to provide ahydrogenated hydrocarbonaceous liquid phase and a hydrogen-rich gaseousphase. The contact of the hydrocarbonaceous effluent from the secondhydrogenation zone with the absorber solution may be performed in anyconvenient manner and in one embodiment is preferably conducted by acountercurrent contacting of the hydrocarbonaceous effluent with wateror a lean aqueous scrubbing solution in an absorber or an absorptionzone. An absorber solution rich in water-soluble hydrogen halide is thenrecovered from the absorber and may be used as recovered or may beregenerated to provide a lean absorber solution which may be recycled tothe absorber to accept additional water-soluble hydrogen halide.

The absorber solution is preferably introduced into the absorber in anamount from about 1 to about 20 times the mass flow rate of the totalfeedstock charged to the second hydrogenation zone based on thecomposition of the effluent from the second hydrogenation zone. Theabsorber is preferably operated at conditions which include atemperature from about 32° F. (0° C.) to about 300° F. (149° C.) and apressure from about atmospheric (0 kPa gauge) to about 2000 psig (13790kPa gauge). The absorber is preferably operated at essentially the samepressure as the second hydrogenation zone subject to fluid flow pressuredrop. In accordance with the present invention, at least somehalogenated organic compounds are introduced as feedstock and thereforethe absorber solution preferably contains water or a lean aqueousabsorber solution containing a water-soluble hydrogen halide. Inaccordance with the present invention the hydrogen halide compound isrecovered by dissolution in water or a lean aqueous solution of thehydrogen halide compound. This permits the subsequent recovery and useof a desirable and valuable hydrogen halide compound. The finalselection of the absorber solution is dependent upon the particularhydrogen halide compounds which are present and the desired end product.The resulting effluent from the absorber containing hydrogenatedhydrocarbonaceous liquid phase and a hydrogen-rich gaseous phase isrecovered and introduced into a separation zone or a vapor-liquidseparator to provide a hydrogen-rich gas stream also containing watervapor and a third hydrogenated stream comprising hydrocarbonaceouscompounds. The water vapor may have originated from an aqueous absorbersolution utilized in the integrated process and/or from thehydrogenation of organic compounds containing oxygen. Regardless of thesource of water, the elimination or at least the minimization of watervapor which enters the hydrogenation zones is exceedingly desirable.This becomes even more critical when the operating temperature in ahydrogenation zone is at or below the dew point of water. With thepresence of a hydrogen halide and water, a corrosive solution is formedwhich is detrimental to conventional metallurgy used to fabricatehydrogenation zones. Although more exotic metals may be used to resistcorrosive substances in absorbers, for example, the use of suchmetallurgy in hydrogenation zones is prohibitively expensive.

The hydrogen-rich gas stream comprising water vapor which is recoveredfrom the above-mentioned separation zone is in one embodiment introducedinto a drying zone to remove at least a portion of the water vapor fromthe hydrogen-rich gas stream. The resulting dried hydrogen-rich gasstream is then preferably recycled to the first and/or the secondhydrogenation zone. The first and/or the second hydrogenation zone maycontain one or more catalyst zones.

In accordance with the present invention, the recycle hydrogen which isrecovered from the absorber effluent in a separation zone is dried in adrying zone utilizing techniques which are known to those skilled in theart. We contemplate that in a preferred embodiment the drying zonecontains an adsorbent which selectively retains water vapor whilepermitting the hydrogen-rich gas to pass through the drying zone. Thedrying adsorbent may be employed in any suitable manner and in one ormore zones. In a preferred embodiment, the adsorbent is housed in atleast two zones in order to permit one zone to be drying thehydrogen-rich gas stream while another is being regenerated. Suitableadsorbents may be selected from molecular sieves, silica gel and calciumchloride, for example. The drying zone is preferably maintained atconditions which include a pressure from about atmospheric (0 kPa gauge)to about 2000 psig (13790 kPa gauge), a temperature from about 40° F.(4.4° C.) to about 200° F. (93.3° C.) and a gas hourly space velocityfrom about 100 hr.⁻¹ to about 5000 hr⁻¹. The drying zone is preferablyoperated at essentially the same pressure as the gas-liquid separationzone used to supply the hydrogen-rich gas stream comprising water vaporto the drying zone.

The preferred catalytic composites disposed within the hereinabovedescribed hydrogenation zones can be characterized as containing ametallic component having hydrogenation activity, which component iscombined with a suitable refractory carrier material of either syntheticor natural origin. The precise composition and method of manufacturingthe carrier material is not considered essential to the requestinvention. Preferred carrier materials are alumina, silica, carbon andmixtures thereof. Suitable metallic components having hydrogenationactivity are those selected from the group comprising the metals ofGroups VI-B and VIII of the Periodic Table, as set forth in the PeriodicTable of the Elements, E. H. Sargent and Company, 1964. Thus, thecatalytic composites may comprise one or more metallic components fromthe group of molybdenum, tungsten, chromium, iron, cobalt, nickel,platinum, palladium, iridium, osmium, rhodium, ruthenium, and mixturesthereof. The concentration of the catalytically active metalliccomponent, or components, is primarily dependent upon a particular metalas well as the physical and/or chemical characteristics of theparticular hydrocarbon feedstock. For example, the metallic componentsof Group VI-B are generally present in an amount within the range offrom about 1 to about 20 weight percent, the iron-group metals in anamount within the range of about 0.2 to about 10 weight percent, whereasthe noble metals of Group VIII are preferably present in an amountwithin the range of from about 0.1 to about 5 weight percent, all ofwhich are calculated as if these components existed within the catalyticcomposite in the elemental state. It is further contemplated thathydrogenation catalytic composites may comprise one or more of thefollowing components: cesium, francium, lithium, potassium, rubidium,sodium, copper, gold, silver, cadmium, mercury and zinc. Preferredhydrogenation catalysts comprise alumina and palladium.

As described above, the resulting hydrogenated hydrocarbonaceous liquidphase is preferaly recovered from the hydrogen-rich gas phase in aseparation zone which is maintained at essentially the same pressure asthe scrubber and as a consequence contains dissolved hydrogen and lowmolecular weight normally gaseous hydrocarbons if present. In accordancewith the present invention, it is preferred that the hydrogenatedhydrocarbonaceous liquid phase comprising the hereinabove mentionedgases be stabilized in a convenient manner, such as, for example, bystripping or flashing to remove the normally gaseous components toprovide a stable hydrogenated distillable hydrocarbonaceous product. Insome cases, we contemplate that a significant portion of thehydrogenated hydrocarbonaceous product may comprise methane, ethane,propane, butane, hexane and admixtures thereof. An adsorbent/stripperarrangement may conveniently be used to recover methane and ethane.Fractionation may conveniently be used to produce purified productstreams such as liquid propane or LPG containing propane and butane.

In the drawing, the process of the present invention is illustrated bymeans of a simplified flow diagram in which such details as total numberof reaction zone and drier vessels, pumps, instrumentation,heat-exchange and heat-recovery circuits, compressors and similarhardware have been delected as being non-essential to an understandingof the techniques involved. The use of such miscellaneous appurtenancesare well within the purview of one skilled in the art.

With reference now to the drawing, an unsaturated halogenated organicfeed stream containing halogenated organic compounds is introduced intothe process via conduit 1 and is contacted with a dried hydrogen-richgaseous recycle stream which is provided via conduit 13 and ishereinafter described. The unsaturated halogenated organic feed streamcontaining halogenated organic compounds and the dried hydrogen-richgaseous recycle stream are introduced into hydrogenation reaction zone2. The resulting hydrogenated organic stream is removed fromhydrogenation reaction zone 2 via conduit 3, is admixed with a secondfeed stream containing saturated, halogenated organic compoundsintroduced via conduit 4, and is introduced into hydrogenation reactionzone 5 without intermediate separation thereof. The resultinghydrogenated hydrocarbonaceous stream is removed from hydrogenationreaction zone 5 via conduit 6, is cooled in heat exchanger 7 andintroduced into absorber 8 via conduit 6. The hydrocarbonaceous streamis contacted in a countercurrent flow with an aqueous halide-leanabsorber solution which is introduced via conduit 9. An aqueoushalide-rich stream is removed from absorber 8 via conduit 10. Aresulting stream containing hydrogenated hydrocarbonaceous compounds isremoved from absorber 8 via conduit 11 and is passed via conduit 11 intohigh pressure vapor/liquid separator 12. A hydrogen-rich gaseous streamcontaining water vapor is removed from high pressure vapor/liquidseparator 12 via conduit 13, passed through drying zone 15 to produce adried hydrogen-rich gaseous stream having a reduced concentration ofwater vapor transferred via conduit 13 and recycled as describedhereinabove. Since hydrogen is lost in the process by means of a portionof the hydrogen being dissolved in the exiting liquid hydrocarbon andhydrogen being consumed during the hydrogenation reaction, it isnecessary to supplement the hydrogen-rich gaseous stream with make-uphydrogen from some suitable external source, for example, a catalyticreforming unit or a hydrogen plant. Make-up hydrogen may be introducedinto the system at any convenient and suitable point, and is introducedin the drawing via conduit 14. A liquid hydrogenated hydrocarbonaceousstream containing hydrogen in solution is removed from high pressurevapor/liquid separator 12 via conduit 16 and is introduced into lowpressure vapor/liquid separator 17. A gaseous stream containing hydrogenis removed from low pressure vapor/liquid separator 17 via conduit 18and recovered. A liquid distillable hydrogenated hydrocarbonaceousproduct is removed from low pressure vapor/liquid separator 17 viaconduit 19 and recovered. In the event that the liquid distillablehydrogenated hydrocarbonaceous product removed via conduit 19 ispropane, for example, the low pressure vapor/liquid separator 17 may benecessarily operated at a pressure in the range from about 300 psig(2068 kPa gauge) to about 500 psig (3447 kPa gauge). In the event thatthe feed stream contains water, this water is recovered from absorber 8via conduit 10 together with the halide-rich absorber solution ashereinabove described.

The following example is presented for the purpose of furtherillustrating the process of the present invention, and to indicate thebenefits afforded by the utilization thereof in producing a distillablehydrogenated hydrocarbonaceous product.

EXAMPLE

An unsaturated, halogenated organic feedstock having the characteristicspresented in Table 1 was charged at a rate of 68 mass units per hour toa first hydrogenation zone containing a palladium on alumina catalystwhich was conducted at hydrogenation conditions which included atemperature of 176° F. (80° C.), a pressure of 750 psig (5171 kPa gauge)and a hydrogen circulation rate of 50,000 SCFB (8427 normal m³ /m³).

                  TABLE 1                                                         ______________________________________                                        Unsaturated, Halogenated Hydrocarbonaceous                                    Feedstock Properties                                                          ______________________________________                                        Specific Gravity @60° F. (15° C.)                                                     1.1955                                                  Distillation, °C.                                                      IBP                   94                                                       5                    97                                                      10                    98                                                      50                    102                                                     90                    113                                                     95                    130                                                     EP                    134                                                     % Over                97                                                      % Residue             3                                                       Composition, Weight Percent                                                   Chlorinated Propenes  64.7                                                    Chlorinated Propane   26.8                                                    Chlorinated Alcohols  0                                                       Chlorinated Ethers    0                                                       Chlorinated Hexadiene 0.7                                                     Chlorinated Hexane    --                                                      Chlorinated Benzene   0.2                                                     Other                 7.6                                                     ______________________________________                                    

The resulting effluent from the first hydrogenation zone and asaturated, halogenated organic feedstock having the characteristicspresented in Table 2 in an amount of 102 mass units per hour was chargedto a second hydrogenation reaction zone containing a palladium onalumina catalyst which was conducted at hydrogenation conditions whichincluded a temperature of 600° F. (315° C.), a pressure of 750 psig(5171 kPa gauge) and a hydrogen circulation rate of 25,000 SCFB (4213normal m³ /m³).

                  TABLE 2                                                         ______________________________________                                        Saturated, Halogenated Hydrocarbonaceous                                      Feedstock Properties                                                          ______________________________________                                        Specific Gravity @60° F. (15° C.)                                                     1.3824                                                  Distillation, °C.                                                      IBP                    96                                                      5                    119                                                     10                    132                                                     50                    156                                                     90                    252                                                     95                    258                                                     EP                    259                                                     % Over                 96                                                     % Residue              4                                                      Composition, Weight Percent                                                   Chlorinated Propenes  --                                                      Chlorinated Propane   49.8                                                    Chlorinated Alcohols  12.1                                                    Chlorinated Ethers    31.1                                                    Chlorinated Hexadiene --                                                      Chlorinated Hexane     3.4                                                    Chlorinated Benzene   --                                                      Other                  3.6                                                    ______________________________________                                    

The resulting effluent from the second hydrogenation reaction zone wascontacted with an aqueous halide-lean solution to recover 65 mass unitsof hydrogen chloride and was found to contain 38 mass units ofhydrocarbonaceous products having the characteristics presented in Table3. A hydrogen-rich gas stream comprising an equilibrium amount of watervapor was recovered and dried in a drying zone containing molecularsieves at a pressure of about 750 psig (5171 kPa gauge) and atemperature of 100° F. (37.8° C.).

                  TABLE 3                                                         ______________________________________                                        Hydrocarbonaceous Product Stream Properties                                   Composition, Weight Percent                                                   ______________________________________                                        Ethane              0.3                                                       Propane             96.6                                                      Chlorinated Propane Trace                                                     Butane              Trace                                                     Pentane             0.0                                                       Hexane and Nonane   3.1                                                                           100.0                                                     ______________________________________                                    

The foregoing description, drawing and example clearly illustrate theadvantages encompassed by the process of the present invention and thebenefits to be afforded with the use thereof.

What is claimed:
 1. A process for the simultaneous hydrodehalogenationof a first feedstock comprising unsaturated, halogenated organiccompounds and a second feedstock comprising saturated, halogenatedorganic compounds which process comprises:(a) contacting said firstfeedstock comprising unsaturated, halogenated organic compounds with afirst dried hydrogen-rich gas stream in a first hydrogenation reactionzone operated at hydrogenation conditions selected to minimize thepolymerization of unsaturated organic compounds and to produce a firsthydrogenated stream comprising hydrocarbonaceous compounds; (b) reactingat least a portion of said first hydrogenated stream comprisinghydrocarbonaceous compounds and said second feedstock comprisingsaturated, halogenated organic compounds with hydrogen in a secondhydrogenation reaction zone operated at hydrogenation conditionsselected to produce a second hydrogenated stream comprisinghydrocarbonaceous compounds and to generate at least one water-solublehydrogen halide compound; (c) containing said second hydrogenated streamwith a halide-lean absorber solution in an absorption zone; (d)withdrawing a halide-rich absorber solution containing at least aportion of said water-soluble hydrogen halide compound from saidabsorption zone; (e) withdrawing a first stream comprising hydrogenatedhydrocarbonaceous compounds and a hydrogen-rich gas from said absorptionzone; (f) introducing said first stream recovered in step (e) into aseparation zone to produce a hydrogen-rich gas stream comprising watervapor and a second stream comprising hydrogenated hydrocarbonaceouscompounds; (g) removing at least a portion of said water vapor from saidhydrogen-rich gas stream comprising water vapor in a drying zone toproduce a second dried hydrogen-rich gas stream; and (h) recycling atleast a portion of said second dried hydrogen-rich gas stream to step(a) as said first dried hydrogen-rich gas stream.
 2. The process ofclaim 1 wherein said first feedstock comprising unsaturated halogenatedorganic compounds comprises a component selected from the groupconsisting of fractionation column bottoms in the production of allylchloride, fractionation column bottoms in the production of ethylenedichloride, fractionation column bottoms in the production oftrichloroethylene and perchloroethylene, used dielectric fluidcontaining polychlorinated biphenyls (PCB) and chlorinated benzene, usedchlorinated solvents, and mixtures thereof.
 3. The process of claim 1wherein said second feedstock comprising saturated, halogenated organiccompounds comprises a component selected from the group consisting offractionation bottoms from the purification column in epichlorohydrinproduction, carbon tetrachloride, 1,1,1 trichloroethane, chlorinatedalcohols, chlorinated ethers, chlorofluorocarbons and admixturesthereof.
 4. The process of claim 1 wherein said first hydrogenationreaction zone comprises at least two catalyst zones.
 5. The process ofclaim 1 wherein said second hydrogenation reaction zone comprises atleast two catalyst zones.
 6. The process of claim 1 wherein said firsthydrogenation reaction zone is operated at conditions which include apressure from about atmospheric (0 kPa gauge) to about 2000 psig (13790kPa gauge), a maximum catalyst temperature from about 122° F. (50° C.)to about 850° F. (454° C.) and a hydrogen circulation rate from about200 SCFB (33.7 normal m³ /m³) to about 100,000 SCFB (8427 normal m³/m³).
 7. The process of claim 1 wherein said second hydrogenationreaction zone is operated at conditions which include a pressure fromabout atmospheric (0 kPa gauge) to about 2000 psig (13790 kPa gauge), amaximum catalyst temperature from about 122° F. (50° C.) to about 850°F. (454° C.) and a hydrogen circulation rate from about 200 SCFB (33.7normal m³ /m³) to about 100,000 SCFB (8427 normal m³ /m³.
 8. The processof claim 1 wherein said halogenated organic compounds comprise a halogenselected from the group consisting of chlorine and fluorine.
 9. Theprocess of claim 1 wherein said water-soluble hydrogen halide compoundis selected from the group consisting of hydrogen chloride and hydrogenfluoride.
 10. The process of claim 1 wherein the effluent from saidsecond hydrogenation zone containing said water-soluble hydrogen halidecompound is contacted with an aqueous solution to recover saidwater-soluble hydrogen halide compound.
 11. The process of claim 1wherein said absorption zone is operated at conditions which include atemperature from about 32° F. (0° C.) to about 300° F. (149° C.) and apressure from atmospheric (0 kPa gauge) to about 2000 psig (13790 kPagauge).
 12. The process of claim 1 wherein said absorption zone isoperated at essentially the same pressure as said second hydrogenationzone.
 13. The process of claim 1 wherein said halide-lean absorbersolution is introduced into said absorption zone in an amount from about1 to about 20 times the mass flow rate of the total feedstock charged tothe second hydrogenation zone.
 14. The process of claim 1 wherein saidfirst hydrogenation zone contains a hydrogenation catalyst comprisingalumina and palladium.
 15. The process of claim 1 wherein said secondhydrogenation zone contains a hydrogenation catalyst comprising aluminaand palladium.
 16. The process of claim 1 wherein said drying zone isoperated at essentially the same pressure as said separation zone instep (f).
 17. The process of claim 1 wherein said drying zone containsan adsorbent selected from the group consisting molecular sieves, silicagel and calcium chloride.
 18. The process of claim 1 wherein said dryingzone is operated at conditions which include a pressure from aboutatmospheric (0 kPa gauge) to about 2000 psig (13790 kPa gauge), atemperature from about 40° F. (4.4° C.) to about 200° F. (93.3° C.) anda gas hourly space velocity from about 100 hr.⁻¹ to about 5000 hr.⁻¹.19. The process of claim 1 wherein said drying zone comprises at leasttwo drying zones.